4.10s are good enough for me. (365 RWHP)

Once I put ported heads on, I will get a 12 bolt with 3.90s.

I think it depends a lot on what kind of power you'll be putting down.

 

I've got ported heads with a stock cam right now.. I was thinking about doing a bigger cam with the gears, to remove my power below 2000 rpm and turn it into power at 5000 rpm..

I've got a few mods like long tubes, so I'm probably making around or maybe slightly above 300rwhp, but I'm definetly not making near 350 rwhp yet.

I think it might make sense to upgrade to a 12 bolt once I start making 400/450rwhp+, in which case, as you say, I'll be getting new gears anyway, so I can probably pick the right gear for the power then.

Right now, I'm just buying an eaton posi and doing new gears on my 10 bolt, as it blew up the other day on my way to walmart, and the stock auburn posi just sucks.

I think I might go the 4.30 route, as I'll probably not be making much more than 350rwhp until I rebuild the engine... but I still have a little bit of reservation about being that high..

 

Yes, you should be fine with 4.30s and the power you're making, but I don't think they are available for a 10 bolt. The only ones I know of in that area are 4.10s, 4.11s and 4.56s.

 

4.56
lol...
4.10's are aweosme and fun for around town, 4.30's (if you can get them for the 10 bolt) would not be TO dramatic of a jump, i shift like Ion, 1st 3rd, 4th... or 2nd, 4th, 5th.... you'll get used to the feel...

 

I guess US Gears makes 4.30s for the 10 bolt (thats what I almost bought today).. they also had 4.10s and 4.56s.. but I figured that the 4.56s were a bit radical, even for a 6 speed tranny.